1. Field of the Invention
The present invention relates to a telephone answering device having simplified mechanical controls advantageously formed of molded plastic.
2. Description of the Prior Art
The inventor's U.S. Pat. No. 3,780,226 discloses a telephone answering apparatus in which an announcement, precorded on a magnetic tape loop, is transmitted to the telephone line in response to detection of an incoming call. When the announcement is complete, the caller's message is recorded on an incoming message tape. When the user returns to his home or office, the magnetic tape is rewound, and the recorded incoming messages are played back. No call goes unanswered, and the user gets his messages even though he was not present when the call came in.
Such automatic telephone answering devices have become quite popular. However, widespread household use of such an appliance has been hindered by the cost of the answering device. An objective of the present invention is to provide a telephone answering apparatus of extremely low cost.
One of the factors which added to the cost of prior art answering units is the complexity and form of construction of the mechanical controls. A number of functions must be performed by these controls. For example, the following operations must be performed to play back the automatically recorded incoming messages:
(a) the drive mechanism for the outgoing announcement tape loop must be disengaged;
(b) the erase head used to erase the magnetic tape just prior to recording an incoming message must be removed from operative contact with the tape;
(c) the motor and drive mechanism associated with the magnetic tape must be set to rewind the tape;
(d) power to the tape drive motor must be turned on; and
(e) following rewind, the motor and drive mechanism must be reset to drive the magnetic tape in a forward direction onto the takeup reel while keeping power on the motor, and while maintaining the outgoing announcement tape loop in a disengaged condition.
In addition, provision must be made to return the device to the normal answering mode after playback has been completed. Additional controls are required to facilitate the recording of a new outgoing announcement on the tape loop.
In the past, relatively complex mechanical arrangements have been required to accomplish all of these control functions. The mechanisms utilized numerous metal parts that were costly to fabricate, and both complex and time consuming to assemble. An object of the present invention is to provide a telephone answering device having very simplified mechanical controls utilizing a minimum of parts, most of which can be fabricated of molded plastic. Assembly and repair are substantially simplified. Low cost and good reliability are achieved.